The present invention relates to the field of motor vehicle brakes. More precisely, the invention relates to an improved construction of an assembly of a brake actuator which is provided for an electromechanically operated parking brake or an electromechanically operated service brake.
Electrically operated parking brakes are used increasingly often in motor vehicles. They have the advantage that they can be controlled with modern on-board electronic systems, thereby opening up new possibilities for the use of parking brakes in a motor vehicle. For example, by electronically controlling such a parking brake, it is possible to prevent undesirable backward rolling when starting on an incline or quite generally the opening of the parking brake can be made dependent on an appropriate operating point of the vehicle motor.
An electrically operated parking brake generally comprises an electromechanical brake actuator, which applies a closing clamping force to a wheel brake by means of a spindle gear and an axially displaceable brake piston. The brake actuator is substantially defined by a torque-generating motor and gear device which are arranged in a damping manner in a housing. In this instance, the housing often has a plurality of functions. On the one hand, the housing serves to fix and/or centre components of the brake actuator and, on the other hand, to shield the sensitive components with respect to the environment. A particular requirement in terms of the construction of the brake actuator is to shield vibrations of the motor and gear device which occur during operation of the housing in order to suppress undesirable development of noise or even a resonating increase in noise owing to an oscillating housing member.
In the patent application WO 2004/044445 A2, there are described arrangements for supporting components of an electromechanical brake actuator in a housing in a damping manner in order to decrease the noise level of a brake actuator to an acceptable level. In this instance, individual components and/or subassemblies of the brake actuator are shielded in a damping manner with respect to each other or with respect to the housing by a plurality of insulating elements with a predetermined spring and damping constant.
An effective damping is dependent not only on the insulating elements (and the number thereof) but also on the type of arrangement of the components in the housing. In particular, owing to an appropriate concept for the bearing of the motor and gear device in the housing, it is possible to achieve effective noise-damping without complex assembly of a plurality of insulating elements, which also leads to a reduction of the production costs.